Open source refers to a software program or platform with source code that is readily accessible and which can be accessed by anyone. Open source access grants users of an application permission to fix broken links, enhance the design, or improve the original code. This transparency is a huge advantage as people are openly able to read the source code and see vulnerabilities. In the case of Bitcoin, improvements can not be made to the code haphazardly, but users can always contribute suggestions that may gain traction in the broader community of developers.